Heated grid gas anchor



June 24, 1952 R. L. KOCH HEATED GRID GAS ANCHOR Filed July 6, 1950 2 SHEETS-SHEET 2 5 65 ROBERTL. Koci-I 53 INVENTOR.

0 .Fi &4 BYJ ATTOENEY gas anchor.

Patented June 24, 1952 HEATED GRID GAS ANCHOR Robert L. Koch, Dallas, Tex., assignor, by mesne assignments, to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation of New York Application July 6, 1950, Serial No. 172361 This invention relates to gas anchors and relates more particularly to a heatecl grid gas anchor.

' In the'production of petroleum oil from subterranean reservoirs, the oil may be recovered Originally as a result of the natural formation pressure forcing the oil from the reservcir to the surface of the ground. As production continues, however, the natural formation pressure decreases until ultimately it becomes insufiicient to force the oil to the surface of the ground. At this point, production is customarily continued by employing pumps to bring the oil to the surface of the ground. Pumping is an effective means for recovering oil from a subterranean reservoir,.but the use of pumps is attended with certain diniculties, particularly those arising from the presence of free or dissolved gases produced concomitantly with the oil. The free gases can enter the pump to cause vapor looking of the pump or to reduce its volumetric eiiiciency, and the dissolved gases, because of the decrease of the pressure on the oil as it enters the pump, tend to escape from solution in the oil resulting in the formation of a foam or a free gas phaseto cause vapor locking of the pump or to reduce its Volumetric efiiciency. In order 'to separate the free gases concomitantly produced with the oil, a gas anchor is customarily employed in conjunction with the pump. However, the use of a' gas anchor of the type usually employed does not ordinarily solve the problems arising from foaming or the formation of a free gas phase as a result of the escape of dissolved gases from the oil upon entrance of the oil into the pump.

It is an object of this invention to provide a It is another object of this invention to prevent foaming of oil upon entry into an oil well pump. It is another object of this invention to minimize formation of a free gas phase by escape of dissolved gas from petroleum oil upon entry of the oil into an oil well pump. It is another object of this invention to reduce the viscosity of oil entering an oil well pump. It is another object of this invention to facilitate separation of gas from oil within an oil well bore.

With the above and other objects in view, as will appear hereinafter, reference is directed to the accompanying drawings in which:

Figure 1 is an elevation in section of a gas anchorconstructed in accordance with one embodiment of the invention, the view showing the well casing and pump;

Figure 2 is a plan view of Figure 1;

Figure 3 isa side view of a heating grid within the gas anchor;

6 Claims. (01.-183-32) Figure 4 is an isometric view, partly cut away. of the inner barrel of the gas anchor; and

Figure 5 is an isometric View, partly in section, of the outer barrel of the gas anchor.

Referring now to the figures, the gas anchor comprises an inner barrel 9, an outer barrel III, an outer barrel cover ll, wall sections I`2, [3, M. !5, 28, and 2l forming segmental chambers 22, 23, 24, 25, 33, and 31 within the annulus between the barrels, heating grids 32, 33, and 34 within chambers 23, 25, and 3l, respectively, and a floor closure or partition 35 forming an oil collecting chamber 36 within the inner barrel 9. The gas anchor, as shown, is positioned at the end of the Well tubing 31 containing oil well pump 38. While one particular type of pump is illustrated, any suitable type of oil well pump may be emplayed.

Inner barrel 9 comprises an elongated cylinder having a diameter sucient to acco-mmodate the oil well tubing 31 and attached thereto are the wall sections l2, l3, 14, !5, 20, and 2l. The wall sections may be integrally connected to the cylinder, as shown, as by casting the cylinder and the wall sections in one piece. However, the wall sections may be attached to the cylinder by any e suitable means such as welds. bolts, rivets, etc.

The wall sections extend to the bottom edge of the cylinder but only wall sections I'2, !4, and 20 extend to the upper edge of the cylinder, wall sections I 3, !5, and 2l extending to a point sufficiently below the upper edge of the cylinder to provide a weir, as hereinafter more fully explained. The inner barrel is provided with a port between each of segmental chambers 22, 26, and 30, ports 39 and 40 being shown, and chamber 36 formed by the floor partition 35, the barrel, and the bottom sections of the well tubing 31.

To the surface of the upper edge of the inner barrel are attached, by suitable means, two arouate plates 44 and. 45 provided with bolt holes 46 and 41, respectively, to accommodate bolts 50 and 51, respectively, for attaching the anchor to the well tubing 31. Wall sections !2, !4, and 20 are provided at their upper and lower edges with dogs 52 having bolt holes 53 to `cooperate with bolt holes 54 in the outer barrel w for attaching the outer barrel to the dogs by means ofbolts 55. The dogs may be attached to the wall sections by any suitable means such as welds, bolts, rivets, or may be integrally connected with the wall sections as by casting the wall sections and the dogs in one piece. Attached to the outer face of the inner barrel 9 are a plurality of hangers 60. The hangers are preferably attached to the barrel 9 by welds or other means that will not involve protrusion of a member beyond the inncr face or the barrel interfering with the reciprocating motion of the pump 30. Floor partition 35 is positioned by attaching to the face of the bottom edge of barrel 9 or to the wall sections 12, [3, !4, l5, 20. and 2l' or to both, or to one or more but not all of the wall sections, as desired. However, regardless of the method of attachment, the abutting surfaces of the floor partition, the face of the barrel, and the wall sections should -be sufliciently close or be sealed in order to prevent leakage therebetween of no more than inconse quential amounts of oil and gas. The sameis true with respect to the abutting edges of the wall sections and the outer surface ot the inner barrel. Heating grids 32, 33, and 34 are positioned within the segmental chambers 23, 25, and 3-! formed by the inner barrel 9, the outer barrel o, the wall sections 'l2, l3, ll, !5, 20 and 2l, and the floor partition 35, and are supported thcrein by means o! the hangers 60; The heating grids 32, 33, and 34 maybe of any desired type, for example. the grids may 'be electrieally operated heating elements, 'stea'm heated tubes, hot water heated tubes, oil heated tubes, etc. In the embodiment illus'trated, tubes heated by steam, water, oil, etc., are employed.

The heating gr'ids are shaped in such :manner that linear flow of oil without interference by the' heating grids is eliminated or at least minimized whereby channeling of oil is eliminated or minimized and efiective heating is obtain'ed. In the embodiment illustrated, the heating grid, referring to Figures 1, 2, and 3, extends from one wall partition to the other wall partition following the arcuate shape of the inner and outer barrels and each loop' of the grid is displaced a slight distance radially from the succeeding loop. By this arrangement, an unobstru'cted passage for 'flow of oil through the segmental chambers is not present, the oil 'follows a devious passage, agitation during flow occurs, and effective .heating of the oil is obtained.

Heating medium for the grids is supplied thereto from a suitable source through line 61 leading to grid 34. The heating medium leaves grid 34 through line 52 leading through suitable opeiing's in floor partition 35, such as opening 53, and passes through grid 32. After passage through grid 32, the heating medium 'passes through line 64 to gr'id 33 and then passes through line 55 to be conducted away from the enchor' for rcheating.

The outer barrel I'll comprises an elongated y c'yiinder adapted to fit over the' inner barrei and to contact at its inner face the wall sections [2, 1'3, M, l5, 20, and 21. The abu'tting surfaces of the wall sections and the inner `face of the barrel and 'the face of the periphery of the floor partition 35 should be sufnciently close or be sea'led, similarly to the abutting surfaces of the 'floor partition, the outer face of the inner' bari-el, and the wall sections, to prevent leakage' therebetween of no more than inconsequential amounts of oil. The upper edge of the b'arrel in contains threads 66.

The barrel 'n is provided at three sections TI), TI, and 12, these 'sections 'corresponding to the p'ortions of the barrel 'n adjacerit to the segmental charnbers 23, 25, and 3 l, with a plurality of oil entry ports 13, which may be in the form of Slots. The sections TB, 11, and 12' extend along 'the' barrel from a point above 'the point where the barrel contacts the floor partition 35 to a point which preferably is not above one-half of the length of the segmental chambers. However, the length of the sections may be as small or as large as desired depending upon the rate of oil flow. the temperature of the heated grids, and the temperature to which the oil is to be heated. The width of the sections ID, 11, 'and 12 should be no greater than the width of the segmental chambers 23, 25, and 3l. Closing the bottom of the outer barrel lo is a cover 14.

The barrel cover ll fits on outer barrel u by cooperation of threads 51 and threads BE and the well tubing passes through the throat 15 of the cover. The cover is provided with a gas outlet 16 comprising a nipple 11 containing a ball valve 18 normally positioned on valve seat 1'9 by valve spring 80. The cover is also provided with ports 81 and 82 to accommodate lines *61 and 65. To prevent leakage of oil from the well past the cover to within the 'anchor the cover is provided with 'gasket rings 33, 84, 85, and 86'.

With' the anchor assembled and positioned at the bottom of the well tubing 31, heating fluid fiowing thronugh the grids, and with the pump 38 Operating within the tubing. petroleu-m 'from the well enters the lower portion of the segmental chambers '23, 25, and 3'l through theperforated sections 10, 11, and 12 and flows upwardly through the chambers over the heated grids. As a result of passage over the :heated grids, the oil is heate'd whereby the dissolved gases are removed from the oil. Furthr, as a result of passage of the oil over the heatefi grids, producing agitation as well as heating of theoil, foarn produced as a result of the release of dis'- solved gas is broken. The oil flows upwafdly through the segm'ental chambers until it reaches the level of the wall sections !3, 15, ,and 21.. These wall sections, being at a lower level than the wall sections 1 2, ll, and 20, provide 'weirs and the oil fiows over' the weirs into the segmente! chambers 22, 24, and 35 and :thence downwardly therethrough. During passage downwardly through the chambers 22, 24, and 30, time is provided for further release of dissolved gas 'from the oil and for breaking of foam, and, 'because of the reduced viscosity of the heated oil, the slip velocitv of released gas is increased .minimizing entrainment of released gas. The heated oil ente's the chamber 35 through the porte, such eis-porta 35 and 40, in the segmental' chambers '22, 24, 38. The reieased gas flowing upwa'dly through 'the chambers leaves' the anchor through the dutlet 16 and flows upwardly through the well between the casing (not shown) and the tubing, flow of oil through the gasoutlet into the anchor being prevented by the ball valve 18.

The pump 38 operates by reciproc'at'ing menon within the tubing 31 'and is aetivated'by 'a sucker rod (not shown) adapted to be attached to the threaded end 90 of the pump. Upon Upward motion 'of the pump, oil ficws from the (member 3'5 into the tubing through port 3 l d'isplacing hall valve `92. Upon downward motin o the pur'hp'; the oil which 'has entered the tubing is' forced into chamber 93 through port 94 provided with ball valve 95, ball vaive 92 closing port 91 'With the next upward movement of the camp. b h vai-ve '95 closes port- 94 andthe' oil 'in the chember 53- is carried with the 'pump to be displaced through port 93 into the tubing upen the down-ward movement of the pump; W

Having thus described my inventin, it` be understood that such descriptionhas been' glven by way of illustration and example and way of limitation, reference for the latter purpose being had to the appended claims.

I claim:

1. A gas anchor comprising in combination an inner chamber adapted for communication with the tubing of a pumping oil well, a plurality ot chambers surrounding said inner chamber, a heating grid in at least one but not all of said chambers surrounding said inner chamber, an oil entry port leading from without to within each of said chambers containing a heating grid, an oil entry port leading to said inner chamber from each of the remaining chambers surrounding said inner chamber, means for passage of oil from each of said chambers containing a heating grid to a chamber containing an oil entry port leading to said inner chamber, and means for escape of gas from said chambers surrounding said inner chamber.

2. A gas anchor comprising in combination an inner chamber adapted for communication with the tubing of a pumping oil well, an even number of chambers surrounding said inner chamber, a heating grid in each alternate chamber surrounding said inner chamber, an oil entry port leading from without to each of said chambers containing a heating grid, an oil entry port leading to said inner chamber from each remaining chamber surrounding said inner chamber, means for passage of oil from each chamber containing a heating grid to one adjacent chamber containing an oil entry port leading to said inne-r chamber, and means for escape of gas from said chambers surrounding said inner chamber.

3. A gas anchor comprising in combination an inner barrel, an outer barrel surrounding said inner barrel, closure means for the bottom of said inner barrel and of the annulus formed by said inner barrel and said outer barrel, Wall sections between said inner barrel and said outer barrel orming a plurality of chambers within the annulus formed by said inner barrel and said outer barrel, a heating grid within at least one but not all of said chambers, means for passage of oil from outside said outer barrel to said chamber containing said heating grd, means for passage of oil from said chamber containing said heating grid to a chamber not containing a heating grid, means for passage of oil from said last mentioned chamber to within said inner barrel, and means associated with said outer barrel for escape of gas from within said outer barrel.

4. A gas anchor comprising in combination an inner barrel, an outer barrel surrounding said inner barrel, closure means for the bottom of said inner barrel and of the annulus formed by said inner barrel and said outer barrel, a plurality of wall sections between said inner barrel and said outer barrel forming a plurality of chambers within the annulus formed by said inner barrel and said outer barrel, a heating grid within each of a plurality but not all of said chambers, means for passage of oil from outside said outer barrel to said chambers containing said heating grids, means for passage of oil from each of said chambers containing a heating grid to a chamber not containing a heating grid, means for passage of oil from said last mentioned chamber to within said inner barrel, and means associated With said outer barrel for escape of gas from within said outer barrel.

5. A gas anchor comprising in combination an inner barrel, an outer barrel surrounding said inner barrel, a floor partition closing the bottom end of said inner barrel and the bottom end of the annulus formed by said inner barrel and said outer barrel, a plurality of wall sections between said inner barrel and said outer barrel forming a plurality of chambers extending lengthwise within the annulus formed by said inner barrel and said outer barrel, a heating grid within each of a plurality but not all of said chambers, oil entry ports in said' outer barrel leading to said chambers containing said heating grids, means for passage of oil from each of said chambers containing a heating grid to a chamber not containing a heating grid, oil entry ports in said inner barrel leading to each of said chambers not containing a heating grid, and means associated with said outer barrel for escape of gas from within said outer barrel.

6. A gas anchor comprising in combination an inner barrel, an outer barrel surrounding said inner barrel, a floorpartition closing the bottom end of said inner barrel and the bottom end of the annulus formed by said inner barrel and said outer barrel, an even number of wall sections between said inner barrel and said outer barrel forming a plurality of chambers extending lengthwise within the annulus formed by said inner barrel and said outer barrel, a heating grid within each alternate chamber, an oil entry port through said outer barrel leading to each of said chambers containing a heating grid, an oil entry port through said inner barrel leading to each remaining chamber, means for passage of oil from each chamber containing a heating grid to one adjacent chamber containing an oil entry port through said inner barrel, and means associated with said outer barrel for escape of gas from within said outer barrel.

ROBERT L. KOCH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,820,291 Strandell Aug. 25, 1931 2,52`5,233 Miller Oct. 10, 1950 

